US Republican presidential nominee Donald Trump’s campaign has dismissed assaults by Democratic leaders at the Democratic National Convention as “empty rhetoric”.

On Wednesday night, speaker after speaker, including US President Barack Obama, Vice President Joe Biden, Hillary Clinton’s pick for vice president, Tim Kaine, all attacked Trump, and described him a demagogue and fraud who is not a suitable person to be in the White House.

In response, Trump’s senior policy adviser, Stephen Miller, said the Democratic Party is obsessed with Trump but they “offered no solutions.”

“They described a vision of America that doesn’t exist for most Americans, including the 70 percent of Americans who think our country is on the wrong track,” Miller said. “Never has a party been so disconnected from what is happening in our world.”

Miller said Democrats do not want to deal with reality. “They spoke in cheap, petty terms beneath the dignity of a convention.”

“Their entire message could be summed up as: things are perfect, let’s not change a single thing. So they resorted to the politics of fear, trying to convince Americans not to vote for change,” he added.

In his speech on Wednesday night, Obama censured the Republican presidential nominee for his slogan, “Make America Great Again”.

Meanwhile, Biden called Trump a deadly choice for America’s future. “Donald Trump and all his rhetoric would literally make us less safe.”

Kaine ridiculed Trump’s most questionable promises, like building a wall on the border with Mexico and making them pay for it, destroying Daesh, and assuring the public there’s nothing fishy in his tax returns.

“Folks, you cannot believe one word that comes out of Donald Trump’s mouth!” he stated.

The Democratic rebuke came just hours after Trump reportedly called on Russia to hack into Democratic presidential nominee Hillary Clinton’s email server to obtain unpublished emails.